Final Results - 2nd Hydroponic Fertilizer Experiment

After only 24 days, the final results are in on the 2nd hydroponic fertilizer experiment. As expected, the box with the air stones did exceptionally well. Box 2 with the 4-18-38 and no airstones did what it's been doing all along. Box 3 with Chem-Gro's Hobby Formula performed as well as the 4-18-38. Box 4 with the Fox Farm Grow Big did not go so well. It looked great on April 20, but went downhill from there. In trying to figure out what went wrong, I think the difference is the fact that the first 3 boxes, per the manufacturers recommendations, have Epsom salt added to them. The Fox Farm instructions say nothing about it, so I didn't add any. I will do another test shortly with the Fox Farm product and add Epsom salt. I know it's a good fertilizer, so I shouldn't be having any problems with it.
part 1 video: • Next Hydroponic Fertil...
For anyone interested, the pH levels were as follows, with before/after:
Box 1 with aeration 7.2 / 9.4 went sky high
Box 2 Kratky 4-18-38 7.1 / 7.9 as expected, the ph usually rises for me
Box 3 Hobby Formula 7.4 / 6.8 it went down
Box 4 Fox Farm 6.5 / 6.1 sounds about right
The ph in Box 1 was exceptionally high, but the lettuce showed no signs of problems. I used the same meter and all were tested within a few minutes of each other.
/ mhp.gardener